Cancer is a wily foe. Our tools for fighting the uncontrolled and invasive growth of cells are sometimes effective, often not. Surgery can miss the mark, while chemotherapy and radiation can cause harmful side effects—even cancer, ironically.
Bacteria may one day provide a better tool. Live organisms—natural or genetically modified– can deliver therapy directly to tumors.
The idea is not particularly modern. Back up 150 years. Two German physicians separately observed a few cancers regressing during accidental infections. Across the ocean, an American physician named William Coley noticed that his patient with neck cancer got better after an infection with the same Streptococcus pyogenes infection. Coley developed a vaccine that was used to successfully treat many cancers. For a recap of the fascinating history read here.
A newer account brings us up to date on the science. According to the article titled Potent and tumor specific: arming bacteria with therapeutic proteins, which appears in March 2015 journal called Therapeutic Delivery,
Bacteria may be effective against cancers by:
- Making proteins that kill cancer cells
- Inducing cell death through signaling
- Stimulating immunity
The researchers state:
“Bacteria have also been designed to convert nontoxic prodrugs to active therapeutic compounds. The ease of genetic manipulation enables creation of arrays of bacteria that release many new protein drugs. This versatility will allow targeting of multiple cancer pathways and will establish a platform for individualized cancer medicine.”
Obstacles need to be addressed before the bacterial route becomes operational. Toxicity, sepsis, incomplete kill requiring additional therapies and the daunting task of finding small metastases. Read Bacteria in cancer therapy: a novel experimental strategy in the journal of Biomedical Science for more on this.